package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.conditions.update.LambdaUpdateWrapper;
import com.baomidou.mybatisplus.core.conditions.update.UpdateWrapper;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.ScrollResult;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import lombok.extern.slf4j.Slf4j;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

import static com.hmdp.utils.RedisConstants.BLOG_LIKED_KEY;
import static com.hmdp.utils.RedisConstants.FEED_KEY;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Slf4j
@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {

    @Resource
    private IUserService userService;

    @Resource
    private IFollowService followService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Override
    public Result queryHotBlog(Integer current) {
        // 根据用户查询
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取当前页数据
        List<Blog> records = page.getRecords();
        // 查询用户
        records.forEach(blog->{
            this.isBlogLiked(blog);
            this.queryBlogUser(blog);
        });
        return Result.ok(records);
    }

    @Override
    public Result likeBlog(Long id) {
        //1.获取用户
        Long userId = UserHolder.getUser().getId();

        //2.判断用户是否点赞
        String key=BLOG_LIKED_KEY+ id;
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());

        //3.未点赞
        if(score==null){
            //3.1点赞数+1
            boolean isSuccess = update(new LambdaUpdateWrapper<Blog>()
                    .eq(Blog::getId,id)
                    .set(Blog::getLiked,getById(id).getLiked()+1));
            //3.2用户存入redis中set
            if(isSuccess){
                stringRedisTemplate.opsForZSet().add(key, userId.toString(), System.currentTimeMillis());
            }

        }else {
            //4.已点赞
            //4.1点赞数-1
            boolean isSuccess = update(new LambdaUpdateWrapper<Blog>()
                    .eq(Blog::getId, id)
                    .set(Blog::getLiked, getById(id).getLiked() - 1));
            //4.2用户从redis中set删除
            if(isSuccess){
                stringRedisTemplate.opsForZSet().remove(key,userId.toString());
            }

        }

        return Result.ok();
    }

    @Override
    public Result queryBlogLikes(Long id) {
        String key=BLOG_LIKED_KEY+id;
        //1.查询top5点赞用户
        Set<String> top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if(top5==null || top5.isEmpty()){
            return Result.ok(Collections.emptyList());
        }
        // 2.解析出其中的用户id
        List<Long> ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        String idStr = StrUtil.join(",", ids);
        // 3.根据用户id查询用户 WHERE id IN ( 5 , 1 ) ORDER BY FIELD(id, 5, 1)
        List<UserDTO> userDTOS = userService.query()
                .in("id", ids).last("ORDER BY FIELD(id," + idStr + ")").list()
                .stream()
                .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                .collect(Collectors.toList());
        // 4.返回
        return Result.ok(userDTOS);
    }

    @Override
    public Result saveBlog(Blog blog) {
        //1.获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        //2.保存探店笔记
        boolean isSuccess = save(blog);
        if(!isSuccess){
            return Result.fail("新增笔记失败！");
        }
        //3.查询作者粉丝
        List<Follow> followers = followService.query().eq("follow_user_id", user.getId()).list();

        //4.向粉丝推送笔记
        for(Follow follow:followers){
            log.info("关注："+follow.toString());
            Long userId = follow.getUserId();
            String key=FEED_KEY+userId;
            log.info("存到redis的键值："+key+"----"+userId.toString());
            stringRedisTemplate.opsForZSet().add(key,blog.getId().toString(),System.currentTimeMillis());
        }
        return Result.ok(blog.getId());
    }

    @Override
    public Result queryBlogOfFollow(Long max, Integer offset) {

        // 1.获取当前用户
        Long userId = UserHolder.getUser().getId();
        // 2.查询收件箱 ZREVRANGEBYSCORE key Max Min LIMIT offset count
        String key = FEED_KEY + userId;
        Set<ZSetOperations.TypedTuple<String>> typedTuples = stringRedisTemplate.opsForZSet()
                .reverseRangeByScoreWithScores(key, 0, max, offset, 2);
        // 3.非空判断
        if (typedTuples == null || typedTuples.isEmpty()) {
            return Result.ok();
        }
        // 4.解析数据：blogId、minTime（时间戳）、offset
        List<Long> ids = new ArrayList<>(typedTuples.size());
        long minTime = 0; // 2
        int os = 1; // 2
        for (ZSetOperations.TypedTuple<String> tuple : typedTuples) { // 5 4 4 2 2
            // 4.1.获取id
            ids.add(Long.valueOf(tuple.getValue()));
            // 4.2.获取分数(时间戳）
            long time = tuple.getScore().longValue();
            if(time == minTime){
                os++;
            }else{
                minTime = time;
                os = 1;
            }
        }
        os = minTime == max ? os : os + offset;
        // 5.根据id查询blog
        String idStr = StrUtil.join(",", ids);
        List<Blog> blogs = query().in("id", ids).last("ORDER BY FIELD(id," + idStr + ")").list();

        for (Blog blog : blogs) {
            // 5.1.查询blog有关的用户
            queryBlogUser(blog);
            // 5.2.查询blog是否被点赞
            isBlogLiked(blog);
        }

        // 6.封装并返回
        ScrollResult r = new ScrollResult();
        r.setList(blogs);
        r.setOffset(os);
        r.setMinTime(minTime);

        return Result.ok(r);
    }

    private void queryBlogUser(Blog blog) {
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }

    @Override
    public Result queryBlogById(Long id) {
        //根据id查询博客
        Blog blog = getById(id);
        //非空判断
        if(blog==null){
            return Result.fail("博客不存在！");
        }
        //查询blog用户
        queryBlogUser(blog);

        //查询blog是否被点赞
        isBlogLiked(blog);

        return Result.ok(blog);


    }

    private void isBlogLiked(Blog blog) {
        //1.获取用户
        UserDTO userDTO = UserHolder.getUser();
        if(userDTO==null){
            return;
        }
        Long userId = UserHolder.getUser().getId();

        //2.判断用户是否点赞
        String key=BLOG_LIKED_KEY+ blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        blog.setIsLike(score!=null);

    }


}
